In cooling devices such as freezers, a forced cold air circulating system is used for cooling. According to the forced cold air circulating system, air cooled by a cooling coil is forced to circulate by a cooling fan in a cooling chamber. Therefore, this system has the advantages of: the cooling chamber having less inner temperature irregularity; and the cooling time being shortened.
For example, in a refrigerator-freezer described in JP S62(1987)-169988 A, a cooler and a fan are disposed on a rear face of a freezing chamber, and circulation air from a cooling chamber and the freezing chamber, which is sucked through an inlet port provided at a portion below the freezing chamber, passes through the cooler to be subjected to heat exchange, and then is discharged into the freezing chamber with air blown by the fan. In such a forced cold air circulating system, during the heat exchange by the cooler, moisture contained in the circulation air is solidified, which results in frost being deposited on the cooler. The invention according to JP S62(1987)-169988 A is devised so that the circulation air from the cooling chamber and the circulation air from the freezing chamber join with each other before reaching the cooler, thus reducing the amount of frost deposited on the cooler.
Furthermore, in freezers described in JP H6(1994)-273030 A and JP 3366977 B, a cooler is disposed on a rear face of a freezing chamber, and cold air discharged from a fan provided in front of the cooler cools the inside of the chamber. This configuration is not provided with an air course dedicated to introducing circulation air passed through the cooler to the rear of the fan. Furthermore, since the fan is provided in front of the cooler, circulation air heading for the rear of the fan from the freezer is allowed to flow while bypassing the cooler, thus reducing the amount of frost deposited on the cooler.
In the refrigerator-freezer described in JP S62(1987)-169988 A, however, in order to realize one-way air flow in which circulation air from the inside of the chamber is passed through the cooler to be introduced to the fan, a dedicated air course formed with molded articles and the like is required, which results in an increase in the number of components and makes the configuration complicated. Furthermore, this configuration aims to decrease the frost deposited on the cooler caused by the circulation air from the cooling chamber by using a low-temperature air circulating from the freezing chamber, but is incapable of decreasing the frost on the cooler caused by the circulation air from the freezing chamber.
In addition, although the freezers described in JP H6(1994)-273030 A and JP 3366977 B can decrease the amount of frost deposited on the cooler, there is a need to provide the fan in front of the cooler, which means an increase in the depth dimension. Therefore, this configuration is not suitable for the miniaturization and has difficulty in saving space.